1. Technical Field
The field of this invention is vascular anastomosis.
2. Background of the Invention
Anastomosis is a term used in medicine to describe the union or connection of one tubular structure to another so that the interiors of the tubular structures communicate with one another and transport fluid, e.g. blood, etc. There are generally two types of anastomoses: end-to-end and end-to-side. In an end-to-end anastomosis, the ends of two different tubular structures are joined together. In an end-to-side anastomosis, however, the severed end of one tubular structure is connected around an opening cut into the side of a second tubular structure. Anastomoses have been performed with a variety of different types of tubular structures or vessels in order to achieve a desired patient outcome. Typically, anastomoses are performed between airways, blood vessels, bowel segments, and urogenital tubes. The procedure for connecting blood vessels is referred to as vascular anastomosis.
One of the best known surgical procedures utilizing vascular anastomoses is the coronary artery bypass. In the context of coronary artery disease, the flow of oxygenated blood to the myocardium of the heart is impeded or compromised by a stenosis or obstruction in the coronary artery. This flow can be improved by providing a coronary artery bypass graft (xe2x80x9cCABGxe2x80x9d) which diverts blood flow around the stenosis, thereby restoring myocardial circulation. In these procedures, a graft (e.g. a saphenous vein graft or a synthetic graft) is harvested and attached to the host vessel on either side of the stenosis utilizing an end-to-side anastomosis at each attachment site. Vascular anastomosis also finds use in the treatment of peripheral vascular occlusions, in which an occluded region of a peripheral vessel, usually an artery, is bypassed.
One problem experienced in anastomosis procedures is calcification of the anastomosis site, i.e. the presence of calcium phosphate mineral at the site of anastomosis. The presence of calcium phosphate mineral at an anastomotic site can render the vascular tissue at the site rigid and difficult to manipulate, and thereby potentially leading to complications during the anastomosis procedure.
Accordingly, there is interest in the development of a method to reduce the mineralization of vascular tissue at an anastomotic site. Of particular interest would be the development of such a method that was simple to perform and would make the anastomotic site more amenable to manipulation, e.g. would return the anastomotic state to a less rigid condition.
Relevant Literature
Articles discussing anastomosis at calcified vascular sites include: Quixc3x1ones-Badrich et al., Am. J. Surg. (August 1993) 166:117; Semel et al., Ann. Vasc. Surg. (January 1988) 2:73-74; and White and Gass, Surg. Gynecol. Obstet. (August 1990) 171:165-166.
Methods and devices are provided for at least reducing the mineral content of a region of non-intimal vascular tissue. In the subject methods, an isolated local environment is produced that includes the region of vascular tissue to be treated. The pH of the local environment is then maintained at a subphysiologic level for a period of time sufficient for the desired amount of demineralization to be accomplished. Also provided are devices capable of producing an isolated local environment that includes the target non-intimal region of vascular tissue. The subject methods and devices find use in a variety of applications, including the preparation of vascular anastomotic sites during vascular anastomosis procedures.